This invention relates to a method and apparatus for User Equipment reachability subscription/notification to facilitate improved message delivery.
While the invention is particularly directed to the art of mobile telecommunications, and will be thus described with specific reference thereto, it will be appreciated that the invention may have usefulness in other fields and applications.
By way of background, LTE (Long Term Evolution) is a rapidly evolving 3GPP project that aims to improve the UMTS (Universal Mobile Telecommunications System) mobile phone standard to cope with future communication network demands. LTE will improve wireless network efficiency/bandwidth, lower costs and enhance services experience. Specifically, LTE will make use of new spectrum opportunities and offer better integration with other open standards. LTE is composed of LTE RAN (Radio Access Network) (also known as E-UTRAN) along with the EPS (Evolved Packet System, also called Evolved Packet Core).
SMS (or Short Message Service) is a method of communication that sends text between cell phones, or from a PC or handheld to a cell phone. The “short” part refers to the maximum size of the text messages: typically 160 characters (letters, numbers or symbols in the Latin alphabet).
In certain legacy systems there is a legacy CS (Circuit Switch) domain and PS (Packet Switch) domain. In CS and PS domains, the SMS) delivery is retried when the UE (User Equipment) is detected by any NAS (Non-Access-Stratum) procedure such as LAU/RAU (Location Area Update/Routing Area Update), etc. by the MSC/VLR (Mobile Switching Center/Visitor Location Register) or the SGSN (Serving GPRS Support Node). For SMS over IP (Internet Protocol), it is detected via an IMS (IP Multimedia Subsystem) Register by the HSS (Home Subscriber Server), but also by the MSC/VLR or SGSN as the delivery of the SMS message is tried on several domains.
Currently in LTE networks/standards, however, there is no mechanism for the HSS to notify the MME (Mobility Management Entity) that an SMS message has failed to be delivered via SMS over IP and request the MME to notify the HSS when the applicable UE becomes reachable. There is also no mechanism for the MME to notify the HSS of the UE's reachability.
The present invention contemplates a new and improved method and apparatus that resolves the above-referenced difficulties and others.